Length of time when the film or digital sensor inside a camera is exposed to light / From Wikipedia, the free encyclopedia
In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter is open) when taking a photograph.[1]
The amount of light that reaches the film or image sensor is proportional to the exposure time. 1⁄500 of a second will let half as much light in as 1⁄250.
A spoon falling in water, taken at 1⁄2000s
Shutter speed can have a dramatic impact on the appearance and quality of photographs, especially when moving objects are involved. For instance a slow shutter-speed often results in a blurred image as the slight shudder of the shutter itself, or the motion caused to the whole camera by the index pressing on the shutter-release button create vibrations that are faster than the shutter itself; this will cause the appearance of the objects in the view-finder and on the photographs having moved when in fact it is the camera that moved.